Theftpb



May 13 1924.

D. R. COUGHLIN THEFTPROOFELECTRIC LIGHT BULB Original Filed on. 28, 1920 I !Reissued,.May 13, 1924.

Rs. 15,836 UNITED STATES PATENT orrlcs.

DANIEL R. COUGHLIN. F DES MOINES, IOWA, ASSIGNOR, BY MERE ASSIGNMENTS, TO KULP THEFT PROOF LAMB CO., A QORIORA'IION OF ILLINOIS.

'rzmr'rrnoor ELECTRIC-LIGHT BULB.

Original No. 1,437,723, dated December 5, 1922, Serial No. 420

, reissue filed December 28, 1923\ Serial No' 688,221.

I To all w/wmitma-j concern: is of ordinary construction. At the smaller j Be it known that I, DANIEL R. COUGHLIN, end of the bulb or a citizen of the United States, and a resident tended in substantially cylindrical form :of Des Moines, in the county of Polk and away from the body, as at 11. State of Iowa, have invented a certain new At the point of juncture between the body and useful Theftproof Electric-Light Bulb, and the cylindrical extension 11, there is fof which the following is a specification. provided an annular l The object of m invention is to provide the exterior surface of the body 10 near the ian electric-light bulb of simple construction, groove 12, there is provided a smallcran made that it may be inserted into a socket nular groove 13, th for. making proper circuit connections in the be hereinafter more fully referred to. ordina way, and then can not be stolen or' The filament dead or current*-conducting !remove .from the socket. member in the bulb is extended laterally With this and other objects in view, my through the wall of the extension 11,415 at invention consists in the construction, ar- 14, and a drop of solder or the liker15 is parts of my dev1ce,'whereby the objects conside of the glass of the member 11. The" templated areattained, as hereinafter more other filament lead or conductingmembcr fully set forth, pointed out in my claims, 14 is cxtdnded longitudinally through the and ilIuStII'IateId in the accompanying drawmember 11, and hasa similar drop 16 of-solm m w 1c igure l shows a side elevation of an elecber 11. It will, of course-be understood that '04] ht bulb embodying my invention, the filament 11' is connected with the leads I arts being shown in section. 14 and'l4.

Figure 2 shows a top or plan view of the The member 11 is formed with a longied s me with the three ell contact re tudinal groove 17 in' its exterior side wall, as oved. Fi re 8 shows a horizontal, detailed, secing 18 commonly called a threjiadedshell conioms view taken on the line 33 of Fig tact is provided, and is formed withspiral 1; and, screw-threads l9, as is the case in ordinary Fi e 4 shows a horizontal, detailed, secelectric-light bulbs, and is arranged to be ex- 'onawiew taken on the line 4--4 of Figtended over the member 11. Dre 1. I In the installation of the shell contact 18, It is well-known that railroad companies soft plaster of Paris or the like 20 is placed and others sufi'er substantial losses on acin the'groove 17 when the casing is placed count of the theft of electric-lighfbulbs or in position, and this plaster of Paris will globes, which are taken from stations, cars rapidly harden for holding the shell contact and other places to which the public has ac- 18 against rotation on the member 11. f Jess. The lower end or edge of the shell contact It is so easy to remove the ordinary bulb 18 is crim ed or bent inwardly until it is refrom the socket, that itlis found that places ceived in t e groove 12, as illustrated 1111.21. of the kind mentioned, empty houses and Extending through-the shell contact 18 is other places, are frequently robbed ofthese a contact member 22, which will contact with bulbs and the aggregate losses suffered in the the drop16, which forms a contact member. :ountry at large are great. The contact member 22, it will be under It is my urpose to provide a bulb, which stood, is insulated from the shell contact 18 :an be used-in the ordinary way with the in the'ordinary way. Jrdinary socket, and which when once in- In the racticaluse of my improved theftmilled in the socket can not be removed until proof bulb, the bulb is initially screwed into :he bulb is broken. 4 the socket in the ordinary way until the con- In the accompanying drawings, I have tacts are made. The lamp may then be used 158d the reference numeral 10 to indicate the in the usu )od y of an electric-light bulb or globe which If, however, it is desired to render this bulb ,oss, flled October 2a, 1920. Application for globe 10, the glass .is ex 55 groove or i ccess'12. In 60 i e purpose of which wilf rangement and combination of the various placed on the outer end of the lead 14,,out-

der or conducting material outside the memshown in Figures 2 and 3, ends metal cas-- al manner and removed at will.

tween.

2. An electric lamp. comprising a bulb. a shell contact having an insulated center consharply, and it will break cleanly along the line of the groove 13. Thereafter access may be had to the interior of the member 11 and to the edge of the shell contact 19 with the fingers or with a suitable tool, and the shell contact 18 may be unscrewed from the socket and removed, for permitting the installation of a new bulb.

The savin'f tobe accomplished by using the bulb of t type hcreimshown is obvious from the foregoing description.

Changes may be made in the construction of my device, and it is my intention to provide a device comprising an electric-light bulb, so arranged that when it is once installed in the socket, it can. not be removed without breakage, and "it is'm'y urpose to cover by my claims, any modifie forms of structure or use of 'mechanical equivalents, which may be reasonably included within their scope Havin thus described my invention, what I c aim as new and desire to secure by Letters Patent; of the UnitcdStatcs is:

1. An electric lamp comprising a-bulb body having an extension, a threaded shell- -contact mounted on said extension provided with an insulated center contact, said shell contact and bulb body being; provided with means to prevent longitudinal separation and to permit lelatlve rotation therebctween, a filament in said hnlb.- mcans .for

maintaining, connecton between said filament and said shell and center contacts during relative rotation of said. contacts and the bulb body, and frangible means between said shell-contact and said extension to nor;

mally preventvrelative. rotation thcrebetact mounted thelcon. said shell eonlaetand bulb'being rovided with means toprevent longitudinal separation and to permit relative rotation lhcmlu-h'vccn'. a filament in said bulb, means for maintaining' connection. between said filament and said shell and.

center contacts during relative rotation of said contacts .-.nd the bnlb. and frangible means between said shell contact and said bulb to normally prevent relative rotation:

thercb'etween.

3. An electric lamp comprising a bulb, and a shell-contact and anmsulatcd center contact therefor, means fixing the shell contact against longitudinal movement in respect to said bulb member, displaceable means initially fixing said bulb against rotation in respect to said shell contact and purposely designed to be displaced by the.

exertion" of a predetermined force to effect such rotation, a filament in said bulb, and

means for maintaining electrical connection between said filament and said shell and center contacts regardless of the rotati'onof the bulb member with respect to the shell contact.

4. An electric lamp comprising a shell-contact and an insulatedicentcr 00h: tact therefor, rmanently discngageab le means initially xing' said bulb 'against .rotation in respect to said shell contact; and purposely designed to be disengaged by the exertion of a predeiermined force to effect such rotation, a, filament in said bulb, and means for maintainingelectrical connection between said filament and said shelland- I center contacts .legal'dless of the rotation-ofthe bulb member with respect to the shell contact.

contact and a ishellicontact tl1erefo'r',;j for. initially securing thef-bulb against-5m ation in respect. to 'saidfshell contact. said means beingpurposcly designed for permitafter the exertion of a predetermined force -t o'ell'cct independent rotationthereofi as means for maintaining electr cal connection between thclampjfilamcnt and the shell iind center contacts regardless ofthejrotation 'ofi the bulb.

6. In an 'electricv lalrip; a bulb. a -cenjteii f contact andashell contact therefor, .sa'id' lamp being adaptedtolminse'rtcd in a' sock? ct solelv-Jiv rotatingi-the same, mcai'is-for lb agalnst rotat on shell contact-Q fsa 1d center contacts the bulb. i 7. In combination an means preventing longitudinahnovemeiit ,of

depression and initially fixing said. bulb against rotation in respect to said shell eon a'bulb, and

and. L ineans for mmmtaiiiihgclectrical connection ff between the lamp filament and. the shelland 1 regardless of the rotation of 115 letfic: lamp emher including a.bu lb 'and a shellicontact and an insulated center coi i t 'act therefor-(j 120 the shell contact in respectzto isaid-tnlb, said lamp -memberlbcin'gf formed with a. depression .adjacentfsaid" shell contact; per-" permanently 'displaceable' means within said' m tact-until such means isdisplaced'by the-ex ertion of a predetermined force to effect .such rotation, a filament in said bnlb, and

means for maintaining electrical connection an tiiig the bulb lobe independently rotatable between said filament and said shelland center contacts regardless of the rotation of the bulb with respect to the shell contact.

8. In combination, an enclosure for electrical apparatus, a cylindrical shell mounted on said enclosure the shell, said shell being provided with means for engaging a supportin receptacle by turning movement of said shifil, and per manentliy disengageable means i ing sai enclosure against rotation in respect to said shell to normally permit iiisertion and removal of the shell in respect to a receptacle by turning said enclosure, said disengageable means. being purposely designed to be rendered inoperative, to permit removal of the shell, by the exertion of a predetermined force to effect further inward 'turnin' of the enclosure in respect to thereceptac e. 9. In combination,

mounte on said enclosure, said shell conill? aconventional. electrical receptacle so ely by turning movement of said shell contact, ermanently disengageable means initially xing said enclosure against rotation in mallyper'tnit insertion and removal of the shell contact in respect to a receptacle by tprning said enclosure, said disengageable means being designed to be rendered inolperative to permit removal of the shell by t e exertion of a predetermined force to efl'ect further turning of the enclosure after the shell contact has been inserted to operative position in a receptacle, and means for. maintaining electrical connection between the apparatus in said enclosure and said shell, contact regardless of therotation of the enclosure with respect to the shell contact.

10. In combination, an electric lamp bulb provided with a shell'contact, means for mounting thereon the shell contact to be initially fixed against rotation in either-direction in respect thereto, said-means bein purposely designed for permitting said bul to be'rotatable in respect to said contact in either direction after being subjected to a predetermined force to render said means inefi'ective, and means for supplying else- Ill means for preventing un-. authorized removal of the enclosure from,

nitially fix-.

an enclosure for electrical apparatus, a cylindrical shell contact tact being provided with means for engag n spect to said shell contact to nortrical energy to the lamp throu h said shell contact after'such rotation of t e bulb.

11. In combination an electric lamp bulb provided with a substantially cylindrical sup orting shell, said shell being provided wit means for engaging a supgmrtingl ceptacle by turning movement 0 said s ell, means for mounting said-'shell .on the bulb to be initially fixed against rotation in either direction in. named means bein permitting said bu spcct to said shell being subjected to a predetermined force to render said meansinefi'eetive, and means for pgefienting removal of the bulb from the 1-2.An electric lamp comprising a bulb, a threaded shell contact therefor, means rmanentl fixing said shell contact against lon itu inal movement inrespect to said bul .Jdis laceable' means permanentlyim cor orate in the lamp ior preventing said purposely desi ned for b to be rotatab e in-rerespect thereto, said last a in either direction after Elle 1 contact from turning in respect to the ulb while the lamp is beinginserted in a receptacle by turning the bulb, said means being purposely designed to be displaceable by rotation of the bulb to permit the bulb to berrevolved in respect to the contact and thereby to prevent removal of .the lamp from the. receptacle by turn' the bulb, and means for supglym electrical one to the lam throng sai contactafter iii lamp has n revolved in respect to the contact; 7

13.3:An incandescent a bulb, and center and for, the shell contact being in the conventional manner, and connected to .the bulb'so as to permit of'the lamp being screwed into a socket by simple rota: tion of the bulb, said connection bein purposely desi ed to be releasable by orced rotatlono -the bulb after the lamp screwe tome so that the'bulb will then r tate independently ofthe shell contact, and means for maintaining electrical connection between the lamp filament and the contacts notwithstanding such independent rotation of the'bulb.

In testimony whereof, I have hereunto subscribed my name this'22nd day of December, 1 923.

DANIEL R- UQUUHLIN.

consisting of screw-threaded 

